As disclosed in, for example, Japanese Patent Application Laid-open No. 159,274/1994, there has been conventionally known a hermetic sealed compressor, in which a compressing element and a drive motor are contained inside of a casing of a welding structure in a sealed manner. Such a hermetic sealed compressor has a high reliability since an operating fluid cannot leak, and further, there is no danger of intrusion or the like of water when the operating fluid is compressed. Therefore, the hermetic sealed compressor is provided in a refrigerant circuit of a freezer for use in an air conditioner or the like.
The compressing element in the above-described hermetic sealed compressor is configured such that it is driven by the drive motor so as to compress the operating fluid. The compressing element is provided with, for example, a cylinder and a rotary piston.